SXT Status Report February 14, 2000, to March 5, 2000 (Weeks 8-10) H. Hudson, D. McKenzie SUMMARY Routine operations, including struggling a bit more with Y2K software problems. Solar activity increased and yielded an X-class flare on March 2. SOLAR ACTIVITY We had numerous (10 through March 2) M-class flares, and the one X event (AR 8882, a spot group with area ~1,000 millionths). OBSERVING CAMPAIGNS There were no coordinated campaigns. We did however respond to requests for input on the appearance of large-scale interconnecting loops (Farnik) and well-observed streamer bases (Foley). Farnik himself is at Vandenberg watching his instrument being launched; and sure enough, the interconnecting loops again became quite interesting in his absence. We resumed "rapid run" long FFI exposures, obtaining two days of Q-resolution SFD-type images at 32-sec cadence. The idea here is to look for more wave events, especially for flares below the trigger threshold level (about C6 at present). Please see our webpages for more details about campaigns past and future: http://isass1.solar.isas.ac.jp/sxt_co/sxt_catalog.html http://isass1.solar.isas.ac.jp/sxt_co/sxt_future.html SXT INSTRUMENT STATUS AND CALIBRATION ACTIVITIES The redefinition of Yohkoh normal pointing on Feb. 11 caused some small problems. First, the software used for tracking the pointing (part of the QUICK page) suffered from a Y2K bug. Second, almost no terminator opportunities occurred for about two weeks. Third, another software error (again Y2K) resulted in an inadvertent return for two days to the old normal pointing position. However we seem to be on track again. Yet another Y2K problem appeared in the orbit predictions. The problem code was in the mainframe FORTRAN program, and had been translated into the workstation IDL equivalent. So, they both failed. By lightning international e-mail action, a tiger team at ISAS, Palo Alto, Toyokawa, and Mitaka converged quickly on the problem and fixed it. We hope that these three items will be the last of the Y2K problems. We've weathered the leap year too by now. The HXT aspect sensor (HXA) was inadvertently turned off for two days owing to a double error at KSC. Because SXT depends upon these data to calibrate the Yohkoh gyros, there will be no absolute SXT pointing information for (approximately) 17-Feb 18:00 to 19-Feb 19:00. As usual, one must confirm (att.status1 eq 8) to be sure that a good aspect solution exists. SXT OBSERVING SEQUENCE TABLES ------------------------------------------------------------- UT Date & Time Pass Table ID ============================================================= Tuesday 14-FEB-00 20:30 2 00214 P2 ARS1 DIFF 23:55 4 000214 P4 ARS1 DARKCAL Wednesday 16-FEB-00 0:06 4 000215 P4 ARS1 STD Thursday 16-FEB-00 22:36 4 000216 P4 ARS1 STD Friday 17-FEB-00 22:46 4 000217 P4 ARS1 STD Saturday 18-FEB-00 21:15 3 000218 P3 ARS1 STD Sunday 19-FEB-00 16:20 1 000219 P1 ARS1 STD Tuesday AM 21-Feb-00 15:00 1 000222 P1 ARS1 STD* Wednesday AM 22-Feb-00 16:52 2 000223 P2 ARS1 DKCAL* Thursday AM 23-Feb-00 17:03 3 000223 P3 ARS1 DIFF Friday AM 24-Feb-00 17:14 3 000225 P3 ARS1 STD* Saturday AM 25-Feb-00 19:08 4 000225 P4 ARS1 STD Saturday PM 26-Feb-00 14:12 2 000226 P2 ARS1 STD Tuesday AM 28-Feb-00 18:00 4 000228 P4 ARS1 STD Tuesday PM 29-Feb-00 11:22 1 000229 P1 ARS1 STD Wednesday AM 29-Feb-00 16:28 4 000229 P4 ARS1 DKCAL Wednesday PM 01-Mar-00 13:15 2 000301 P2 ARS1 DIFF Thursday PM 02-Mar-00 13:26 3 000302 P3 ARS1 STD Saturday PM 04-Mar-00 13:48 3 000304 P3 ARS1 STD ============================================================ SCIENCE General: At the end of February the MR2000 conference (magnetic reconnection) took place at Tokyo University. Many of the legendary figures of this subject, including three P's (Parker, Petschek, and Priest - but not either Peter) were present. It would be safe to say that definite progress has been made both theoretically and observationally, and of course we have new Yohkoh observations that are quite relevant. Seminars: None. Too many meetings! However, McKenzie gave a talk at NAO Mitaka. Nuggets: 03-Mar-00: An X-class flare with sympathetic brightening. On March 2, our second X-class flare of the current decade occurred. It was extremely impulsive and highly ejective, and was a prototype SDE (Short-Decay Event) in which the flare loop system really seems not to have been much larger than one pixel in soft X-rays. Uri Feldman will no doubt be pleased by this one. 25-Feb-00: X-Ray jet with wavelike deformation. One of the most striking jet events, in the form of a large-scale helix (about one turn) in a highly collimated X-ray jet. This reminds us of the Mees H-alpha obervations described by Canfield et al., in which the rotation of the material could be seen directly in the Doppler motions. 18-Feb-00: Theories, models, and cartoons. Announcing - with random samples - a Web archive of cartoons representing the essential physics of flares and CMEs. There are of course many of these! This archive is likely to grow to great size, because every theorist has several examples, and all want to see their art displayed. We are also extending the contents into the past via scanning the paper representations, and here the ApJ on-line material is extremely helpful. The full list of nuggets is kept on http://isass1.solar.isas.ac.jp/sxt_co/index.html , and the current week's nugget also normally resides on http://isass1.solar.isas.ac.jp/sxt_co/SXTweekly.html . PERSONNEL Phil Shirts arrived for a brief tour. Brian Handy may have mastered Japanese by now but must have returned to Montana. TOHBANS (spacecraft operators) Tohbans for week 10 SSOC: K. Fujiki, T. Ishii KSC: H. Kozu, Y. Yamauchi SXT_CO: H. Hudson SXT_SW: P. Shirts Tohbans for week 09 SSOC: K. Shinoda, H. Nakajima KSC: T. Magara, M. Kozu SXT_CO: D. McKenzie SXT_SW: P. Shirts Tohbans for week 08 SSOC: Y. Kato, T. Sakao, M. Shimojo KSC: T. Yokoyama, T. Magara SXT_CO: H. Hudson SXT_SW: -